Editing Brolga (section)

==Ecology and behaviour==
[[File:Brolga2.jpg|thumb|right|A pair of brolgas amongst other [[waterbird]]s in the [[Northern Territory]]]]
The social unit of brolgas is very similar to that observed in sarus cranes. In breeding areas, breeding pairs defend territories against other brolgas, and when breeding efforts are successful, they remain in territories with one or two chicks.<ref name=":0" /> Nonbreeding birds, being young birds of past years as well as adults that do not yet have breeding territories, are also found in breeding areas, likely throughout the year. In the nonbreeding season, they gather into large flocks, which appear to be many self-contained individual groups rather than a single social unit. Within the flock, families sometimes remain separate and coordinate their activities with one another rather than with the flock as a whole.<ref name=Johnsgard/> In south-western Queensland, 26–40% of all crane sightings were breeding pairs and families in the Gilbert and Flinders river floodplains.<ref name=":0" /> Flocks were relatively rarer, but birds in flocks in the Flinders river floodplain constituted 80% of all brolgas counted. In south-west Victoria,  distinct breeding (spring) and flocking (autumn) seasons are noted.<ref name=":1" />
 	
When taking off from the ground, their flight is ungainly, with much flapping of wings. The bird's black wingtips are visible while it is in the air, and once it gathers speed, its flight is much more graceful and it often ascends to great heights. Here, it may be barely discernible as it wheels in great circles, sometimes emitting its hoarse cry.<ref name=Gould/>

===Diet===
Brolgas are [[Omnivore|omnivorous]] and forage in wetlands, saltwater marshes, and farmlands. They tear up the ground with their powerful beaks in search of bulbs and edible roots.<ref name=Gould/> Northern populations have a very varied diet, with minimal contribution of vegetation.<ref name=":0" /> They also eat the shoots and leaves of wetland and upland plants, cereal grains, [[seed]]s, [[insects]], [[mollusk]]s, [[crustacean]]s, [[frog]]s, and [[lizard]]s. In saltwater marshes, they may drink saline water, as they have [[gland]]s near their eyes through which they [[salt gland|can excrete excess salt]].<ref name=Veyret/> Isotopic analyses of molted feathers in their breeding grounds along the Gulf of Carpentaria showed their diet to be diverse across multiple trophic levels, with minimal contribution of vegetation.<ref name=":0" /> Analyses showed strong niche separation between brolgas and sarus cranes by diet. Their diet in dry season flocks at Atherton Highlands likely are very different owing to the largely agricultural landscape.

===Mating and breeding===

[[File:Brolgas Healesville.jpg|thumb|upright|right|Pair at nest at [[Healesville Sanctuary]] near Melbourne]]
	
Brolgas are [[Monogamy in animals|monogamous]] and usually bond for life, though new pairings may follow the death of one individual. A feature of a bonded couple is the synchronous calling, which the female usually initiates. She stands with her wings folded and beak pointed to the sky and emits a series of trumpeting calls. The male stands alongside in a similar posture, but with his wings flared and primaries drooping, which is the only time when sex can be differentiated reliably. The male emits one longer call for every two emitted by the female.<ref name=Veyret/>

Brolgas are well known for their ritualised, intricate [[mating dance]]s. The performance begins with a bird picking up some grass and tossing it into the air before catching it in its bill. The bird then jumps a metre (yard) into the air with outstretched wings and continues by stretching its neck, bowing, strutting around, calling, and bobbing its head up and down. Sometimes, just one brolga dances for its mate; often they dance in pairs; and sometimes a whole group of about a dozen dance together, lining up roughly opposite each other before they start.<ref name=Johnsgard/>
[[File:Grus rubiconda MHNT 226.jpg|upright|thumb|Egg of ''A. rubicunda'']]
The brolga breeds throughout its range in Australia and New Guinea. The start of the breeding season is largely determined by rainfall rather than the time of year; thus, the season is February to May after the rainy season in the monsoonal areas, and September to December in southern Australia.<ref name=Ber03/> It is unclear whether all breeding pairs leave breeding territories to join flocks during the dry season or return the subsequent breeding season, and this behavior may vary with location. In food-rich [[habitat (ecology)|habitats]], nests can be quite close together, and in Queensland, are found in the same area as those of the sarus crane. The nest, which is built by both sexes, is a raised mound of uprooted grass, and other plant material sited on a small island in shallow water, or occasionally floating. Sometimes, the birds make hardly any nest, take over a disused [[swan]] nest, or simply lay on bare ground.<ref name=Ber03>{{cite book | last = Beruldsen | first = G | title = Australian Birds: Their Nests and Eggs | publisher = self | year = 2003 | location = Kenmore Hills, Queensland | pages = 211 | isbn= 978-0-646-42798-0}}</ref> Nests were initiated between November and February in the Gilbert and Flinders River basins, and tracked rainfall episodes in each river basin.<ref name=":0" />

A single brood is produced per year. The clutch size is usually two, but occasionally one or three eggs<ref name=":2">{{Cite journal|last=Nielson|first=Lloyd|date=1963|title=Unusual clutch of eggs of the Brolga|journal=The Australian Bird Watcher|volume=2|pages=56–57}}</ref> are laid about two days apart. The dull white eggs are sparsely spotted or blotched with reddish brown, with the markings being denser at the larger end of the egg. They measure {{convert|95|by|61|mm|abbr=on}}, though larger eggs were found in a clutch of three eggs.<ref name=Ber03/><ref name=":2" /> Both sexes incubate the eggs, with the female sitting on the nest at night. Hatching is not synchronised, and occurs after about 32 days of incubation. The newly hatched chicks are covered with grey down and weigh about {{convert|100|g|abbr=on}}. They are [[precocial]] and are able to leave the nest within a day or two. Both parents feed and guard the young. The chicks fledge within 4–5 weeks, are fully feathered within 3 months, and are able to fly about 2 weeks later. When threatened, they hide and stay quiet, while the parents perform a broken-wing display to distract the predator. The adults continue to protect the young for up to 11 months, or for nearly 2 years if they do not breed again in the interim.<ref name=Johnsgard/> Breeding pairs maintain discrete territories within which they raise chicks. Territory sizes in Victoria, south-eastern Australia, ranged between 70 and 523 hectares, and each crane territory had a mix of farmland and wetlands.<ref name=":3">{{Cite journal|last1=Veltheim|first1=Inka|last2=Cook|first2=Simon|last3=Palmer|first3=Grant|last4=Hill|first4=Richard|last5=McCarthy|first5=Michael|date=2019|title=Breeding home range movements of pre-fledged brolga chicks, Antigone rubicunda (Gruidae) in Victoria, Australia – Implications for wind farm planning and conservation|url=https://www.sciencedirect.com/science/article/pii/S235198941930037X|journal=Global Ecology and Conservation|volume=e00703|pages=e00703 |doi=10.1016/j.gecco.2019.e00703 |bibcode=2019GEcoC..2000703V |doi-access=free}}</ref> Families roosted in wetlands at night, and moved an average distance of 442 m to and from these night roosts. Each family used multiple wetlands within their territories, either switching between them, or using wetlands sequentially. Breeding success of territorial pairs (estimated as percentage of pairs that successfully fledged at least one chick) was 59% in the Gilbert River basin and 46% in the Flinders River basin (using a total of 80 pairs located on territories), with 33% of all successful pairs fledging two chicks each.<ref name=":0" />